This invention relates generally to trains and, more particularly, to a method for planning a train build.
In a typical train switchyard, trains arrive, and segments of cars (cuts) are set out in a receiving yard. In due course, local switch engines move each cut to a classification yard, separating the cars out of the cut in the process and classifying the cars on distinct tracks of the classification yard. This classification segregates the incoming cars of any given cut for disparate destinations (i.e., for different outbound trains), and aggregates the specific cars into various blocks which are bound for a single destination. Any track in the classification yard at any moment may include a block of cars being assembled for an outbound train.
Once blocks of cars on the classification tracks are completed, another switching crew may move them to a set of departure tracks, where one or multiple blocks will comprise each outbound train. After all of the blocks for an outbound train are available on one of the departure tracks, assigned locomotives may be attached, followed by a final inspection. The train is then ready for departure.
Currently, railroads make train building process decisions manually, and individual yard masters have evolved xe2x80x9crules of thumbxe2x80x9d by which trains are built. Rules of thumb may or may not provide the best solution possible, even if their application generally permits on-time train departures. For example, if the rules of thumb now utilized permit a certain yard throughput, in concordance with the normal flow of trains for the railroad, then those same rules might not support a substantial increase in yard throughput. But, if the railroads automate movement planning and dispatch, they will certainly obtain more capacity from their corridors. However, increased throughput ability will be wasted if the railroads obtain no additional capacity from their yards.
In an exemplary embodiment of the invention, a train build is planned by determining a state of a train yard and then determining the status of resources within the yard. When a resource becomes free, or available, a determination is made regarding possible options for the available resource. The affect of each option on the schedule of outbound trains is then determined. Specifically, the cost of late departures of outbound trains is determined and the option that provides a low (or no) cost of late departure is chosen. If multiple options are available, the departure times of the outbound trains are determined and the option that provides a shortened departure time is chosen.
The method for planning a train build reduces costs associated with late outbound train departures. In addition, the overall timeliness of train departures is improved by reducing the time for building a train, thereby increasing the throughput of a train yard.